Charged particle beam apparatus typically employs a scanning electron microscopy (SEM), which is a known technique used in semiconductor manufacturing. Defects can occur on the mask or wafer during the semiconductor fabrication process, which impact yield to a great degree. Defect inspection systems and defect review systems are two significant means for semiconductor yield management.
Defect inspection system detects particles, pattern anomalies (or defects), and process-induced anomalies and typically detection results from the inspection systems are fed to defect review systems. The information usually is anomalies location with respect to the pattern of semiconductor devices or “defect map” of the device. Defect review system according the defect map further reviews the defect with higher magnification and superior resolution then analyzes defect root causes with Energy Dispersive Spectrometer (EDS). However, an electron beam (e-beam) defect review station is not only receiving defect maps from electron beam inspection system but in the most cases also receiving defect maps from optical defect inspection system.
Beside the higher resolution image, stereo imaging detection for topography analysis (which tells whether defects are protrusion or depression) is also a required function in a defect review system. In addition, wafer surface charging due to electron impinging sample surface is another issue that affecting imaging quality.
In the software portion of a review system, the automatic defect review process is the core technique of success. After loading the defect map, automatic defect locating (ADL), defect review and defect classification (die to die comparison or die to database comparison) are very complicated and time consuming. What is needed is a system and method to address the above-identified issues. The present invention addresses such a need.